In my humble opinion all they needed to do to make the trad more acceptable for a different/wider clientele was to fit some uprated more modern suspension eg wishbone front suspension and sophisticate the rear eg as with the last of the Roadsters setup, They had already introduced air conditioning, power steering maybe an automatic option for wider appeal.
22 Plus Four KIMI 12 Plus 4 Sport OZZY 08 Roadster FELIX 06 4/4 70th LOKI 77 4/4 SEAMUS 85 4/4 MOLLY